Self-driving and autonomous vehicles, as well as ADAS, are very popular these days for scientific, technological, social, and economical reasons. V2X is an important aspect of these technologies. In one aspect of this technology, congestion control is very important for optimum utilization of the limited communication RF spectrum environment and efficiency of the system. In another aspect of the technology, depending on the weather, we would like to adjust the transmission power to have enough power to support the required SNR (signal to noise ratio) and PER (packet error rate) required, but at the same time, not to exceed the power level needed, for optimum/minimum performance requirement.
Both aspects of the invention, the weather data usage invention and the directional antenna usage invention, go under one umbrella called “V2X propagation optimizations”. The core debate of C-V2X vs DSRC centers around receiving antenna diversity.
In our other related/prior applications and patents, we have addressed/discussed V2X and C-V2X as emerging technologies for safety applications. One of the main concerns for an implementation of any V2X technology on a large scale is the issue of congestion control. In large cities and crowded highways during rush hours, each host vehicle can get messages from over 200 other vehicles and several road side units, all working on a small number of channels and a relatively small spectrum band, trying to send and receive messages at the same time. Given the limited bandwidth and data rate for DSRC and even PC5-based CV2X, the system needs to take some steps to limit the traffic over the communication link to enable the network to continue functioning without effecting transportation safety.
Until now the approach to resolve the issue of congestion on the communication link has been to first limit the volume of traffic by limiting the number of messages sent by each device on the link. The second step has then been to reduce the power output, i.e., reducing the range of each vehicle communication, and as such, enable more cars to send message within a geographic region, without interfering with each other. The problem with reducing power output in a typical V2X system (that is using omni direction) is that it will affect the range in the driving direction, and thus, jeopardizing the performance of some of the safety applications.
With respect to the weather effect on signal, here are some of the prior work/references/data:
http://www.unn.edu.ng/publications/files/images/UMEH,%20CHIBUIKE %20DOMINIC.pdf
http://irep.iium.edu.my/47933/1/WIECONECE2015.pdf
https://www.hindawi.com/journals/ijap/2017/8694748/
https://nmi.org.uk/wp-content/uploads/2014/12/AESIN-V2X-Visteon-reserach_MG.pdf
http://scholar.uwindsor.ca/cgi/viewcontent.cgi?article=6481&context=etd
https://arxiv.org/pdf/1604.08734.pdf
https://www.degruyter.com/downloadpdf/j/jee.2012.63.issue-1/v10187-012-0005-y/v10187-012-0005-y.xml
https://www.degruyter.com/view/j/jee.2012.63.issue-1/v10187-012-0005-y/v10187-012-0005-y.xml
http://www.jpier.org/PIERM/pierm16/17.10100303.pdf
http://festag-net.de/doc/ITST-2008_congcontrol.pdf
https://ece.uwaterloo.ca/˜n71u/jrnl_14_IoTJ_LCZSM.pdf
https://www.hindawi.com/journals/ijap/2013/981281/
http://www.ieee802.org/16/tg2orig/contrib/80216cc-99_24.pdf
https://en.wikipedia.org/wiki/Rain # Intensity
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3081171/
http://www.rand.org/content/dam/rand/pubs/reports/2006/R1694.pdf
http://www.philsrockets.org.uk/Rain %20Fades.pdf
http://patentimages.storage.googleapis.com/pages/U.S. Pat. No. 4,705,998-1.png
http://ecjones.org/propag.html
We will provide the solutions for these 2 problems below. Please note that there is no prior art or product in the industry that teaches the following features in our disclosure here (with respect to the 2 issues that are mentioned above).